Recently, since there is a concern that fossil fuels are being exhausted, alternative fuels have been developed. In particular, bioethanol derived from biomass has attracted attention. This is because biomass is a renewable resource, which exists in large amounts on the earth, and can be used without increasing carbon dioxide in the atmosphere (carbon neutral) so as to contribute to the prevention of global warming.
The attempt has been made that fermentation microorganisms that originally cannot utilize main components of soft biomass, such as cellulose or hemicellulose, are modified by bioengineering procedures to attain ethanol fermentation directly from non-edible carbon sources.
As such bioengineering procedures, cell surface engineering are suitably used. Examples of the cell surface engineering include a method using a GPI anchor protein of a cell surface-localized protein. As such a GPI anchor protein, various proteins are known (Patent Documents 1 to 4 and Non-Patent Documents 1 to 5, for example). Meanwhile, a promoter may be involved in the expression of protein in the cell surface engineering. Examples of known promoters exhibiting a high promoter activity in yeast cells include yeast SED1 promoter, GAPDH promoter, PGK1 promoter, ADH1 promoter, and the like (Patent Documents 2 to 4, for example).